DESCRIPTION (taken from the application) Of the genomes sequenced thus far, about 30 percent of the gene products are predicted to be polytopic transmembrane proteins. These hydrophobic proteins catalyze a multitude of essential functions, from oxidative phosphorylation and electron transfer to transport of molecules into and out of cells and intracellular organelles to signal transduction across membranes, and many are important with regard to human disease. Although advances in molecular biology and biochemistry over the past 15 years have led to the characterization, purification and modification of this class of proteins, only a handful of these proteins have been crystallized in a form that allows structure determination at atomic resolution, which is essential for understanding mechanism of action. Furthermore, many membrane proteins require conformation flexibility in order to function, making it imperative to obtain dynamic information as well in order to fully understand function. Thus, a major problem in this area is the difficulty inherent in obtaining structural information at a relevant level of resolution.The purpose of this symposium is to bring together a wide range of key investigators from a diversity of disciplines studying structure/function relationships at the molecular level in polytopic membrane proteins involved in a variety of functions from as many different perspectives as possible. No other such all encompassing conferences specific to this problem have ever been held and it is expected that by bringing such individuals together, discussions will focus the field on the importance of high resolution structure-function studies in order to understand this important class of biological molecules. Thus, this Symposium will cover the remarkable developments that have occurred in the area over the past 30 years, as well as what portends for the future. Due to the fact that this symposium will be so unique it is critical to the careers of graduate students and postdoctoral follows interested in furthering the understanding of these advancing studies. To this end, we have encouraged the session chairs to invite younger investigators whenever possible. In addition, a workshop on "Emerging Techniques" and a poster session are included in the program. We also intend to actively encourage graduate students and postdoctoral fellows to attend the meeting and participate in these sessions.